Enhancing Pipeline Integrity For Oil & Gas: Versatility Of Single Mechanical Seals

<div style="text-align: justify;">&nbsp;</div><div style="text-align: justify;"><p><span data-preserver-spaces="true">The conventional approach to addressing multifluid pipeline pumps has manifested the use of double mechanical seals along with API plan 53 or 54 barrier fluid for better seal face lubrication. This is generally associated with high OPEX, and additional maintenance costs add to the worry of reliability engineers.</span></p><p><span data-preserver-spaces="true">However, with the advent of some changes in the mechanical seal design to withstand fluid phase change, there exists a solution to handle this situation by incorporating a single mechanical seal along with a containment seal&nbsp;</span><span data-preserver-spaces="true">that</span><span data-preserver-spaces="true"> can withstand pressures up to 100 Bar.&nbsp;</span></p><p>&nbsp;</p><h2><span style="font-size: 14pt;" data-preserver-spaces="true">Mechanical Seal Concept</span></h2><p><span data-preserver-spaces="true">The mechanical seal concept includes a containment seal that withstands the full pipeline pressure in the unexpected event of a catastrophic mechanical seal failure of the single product side seal (API 682 4th&nbsp;edition (2CW-CS)).&nbsp;</span><span data-preserver-spaces="true">This</span><span data-preserver-spaces="true">&nbsp;means massive leakage cannot leave the seal gland in an uncontrolled way in any case. To achieve similar safety and environment protection with a mechanical seal in a multiple fluid pipeline pump.&nbsp;</span></p><p><span data-preserver-spaces="true">Compared to the conventional approach, the new mechanical seal design offers several advantages. It eliminates the need for a double pressurized mechanical seal and a pressurized supply system, providing the performance benefits and safety philosophy of a double pressurized seal arrangement at a more cost-efficient single seal arrangement.</span></p><p>&nbsp;</p><p style="text-align: center;"><img src="" width="316" height="330"></p><p>&nbsp;</p><p><span data-preserver-spaces="true">According to the API (American Petroleum Institute),&nbsp;</span><span data-preserver-spaces="true">supply</span><span data-preserver-spaces="true">&nbsp;plans 75 or 76, a connection clears the space between the product and the atmospheric side seal. The pressure differential on the containment seal equals the primary drain/vent pressure, so the leakage to the atmosphere is very low.&nbsp;</span><span data-preserver-spaces="true">If the main seal fails, the contaminant seal acts as a</span><span data-preserver-spaces="true">&nbsp;safety seal.&nbsp;</span></p><p>&nbsp;</p><p style="text-align: center;">The API plan 75</p><p><img style="display: block; margin-left: auto; margin-right: auto;" src="" width="552" height="252"></p><p>&nbsp;</p><p style="text-align: center;">The API plan 76</p><p><img style="display: block; margin-left: auto; margin-right: auto;" src="" width="575" height="341"></p><p>&nbsp;</p><h2><span style="font-size: 14pt;" data-preserver-spaces="true">API plan 75</span></h2><p><span data-preserver-spaces="true">The API plan 75 consists of:</span></p><ul><li style="list-style-type: disc;"><span data-preserver-spaces="true">Leakage collection reservoir</span></li><li style="list-style-type: disc;"><span data-preserver-spaces="true">Level indicator (Level Switch) - installed to determine when the tank needs to be drained</span></li><li style="list-style-type: disc;"><span data-preserver-spaces="true">Pressure gauge (PI - Pressure indicator) - tracks and indicates the mechanical seal leakage</span></li></ul><p><span data-preserver-spaces="true">The seal vendor usually supplies this system. This setup is an emission-free arrangement with the corresponding API supply plan connection. In case of a catastrophic failure of a mechanical seal, the total loss of the mechanical seal faces occurs.&nbsp;</span></p><p><span data-preserver-spaces="true">According to API 682, a standard containment seal arrangement is designed to contain normal leakage under atmospheric pressure but not the full product pressure. In pipeline applications, product pressures up to 100 bar must be contained in case of a catastrophic failure. Therefore, the high-pressure containment seal is designed to hold the full product pressure.&nbsp;</span></p><p><span data-preserver-spaces="true">Thus, by leveraging the benefits of simplicity, cost-effectiveness, and reliability, coupled with careful consideration of installation procedures and operating conditions, the company ensures the safe and efficient transport of crude oil, minimizing the risk of environmental damage and failures.&nbsp;</span></p><p>&nbsp;</p><p><span style="font-size: 10pt;" data-preserver-spaces="true">Source-ATPS&nbsp;</span></p></div><div style="text-align: justify;"><p><span data-ccp-props="{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:279}">&nbsp;</span></p><p>&nbsp;</p><p><span style="font-size: 10pt;"><em>This article was contributed by our expert&nbsp;<a href="" target="_blank" rel="noopener">Vaibhav Khade</a></em></span><br>&nbsp;</p><p>&nbsp;</p><h3><span style="font-size: 18pt;">Frequently Asked Questions Answered by Vaibhav Khade</span></h3><h2 style="text-align: justify;"><span style="font-size: 12pt;">1. Can you elaborate on the cost savings potential for operators when utilizing single mechanical seal technology compared to double mechanical seals?</span></h2><p style="text-align: justify;">Operational efficiency can be achieved by saving nearly 40 %&mdash;50 % on expensive barrier fluid circulation systems.</p><p style="text-align: justify;">&nbsp;</p><h2 style="text-align: justify;"><span style="font-size: 12pt;">2. What measures are taken to ensure the compatibility of single mechanical seals with various types of fluids commonly transported in multifluid pipeline applications?</span></h2><ul style="text-align: justify;"><li>While selecting the faces,&nbsp;elastomers, and hardware, care should be taken for the presence and nature of solid particles, if any</li><li>TC faces can be used,&nbsp;FFKM Orings, and corrosion-resistant hardware in alloy material</li><li>Various combinations exist in API 682 chart to be referred.</li></ul><p style="text-align: justify;">&nbsp;</p><h2 style="text-align: justify;"><span style="font-size: 12pt;">3. What considerations should operators take into account when implementing API Plan 75 alongside single mechanical seals in their pipeline systems?</span></h2><p style="text-align: justify;">Plan 75 must be used for condensing leakage and not for gases. For the gaseous leakage, Plan 76 must be selected.</p><p style="text-align: justify;">&nbsp;</p><h2 style="text-align: justify;"><span style="font-size: 12pt;">4. How do multifluid pipeline pumps with single mechanical seals contribute to the overall efficiency and safety of crude oil transportation operations?</span></h2><p style="text-align: justify;">The configuration of the single seal with a containment seal provides a safe and efficient environment conducive to seal working and simultaneously provides cost benefits.&nbsp;<br>They lower the MTBR due to fewer parts (repair cost) and increase the MTBF (equipment downtime), thereby optimizing throughput.</p><p>&nbsp;</p><p>&nbsp;</p></div><div><p style="text-align: justify;"><span data-ccp-props="{&quot;201341983&quot;:0,&quot;335559739&quot;:160,&quot;335559740&quot;:279}">&nbsp;</span></p></div>
KR Expert - Vaibhav Khade

Core Services

Human insights are irreplaceable in business decision making. Businesses rely on Knowledge Ridge to access valuable insights from custom-vetted experts across diverse specialties and industries globally.

Get Expert Insights Today